du bois



UNITED STATES PATENT OFFICE.

THOMAS E. DU 3018, OF NIAGARA. FALLS, NEW YORK, ASSIGNOR TO U. S. LIGHT & HEAT CORPORATION, OF NIAGARA FALLS, NEW YORK, A. GOIBJOMTION OF NEW YORK.

DYNAMO-ELEOTBIC MACHINE.

Application filed April 22, 1916, Serial No. 92,955.

I '0 all whom it may concern:

Be it known that I, THOMAS R. DU B018, a citizen of the United States, residing at Niagara Falls, in the county ofNiagara and State of New York, have invented new and useful Improvements in Dynamo-Electric Machines, of which the following is a specification.

The present invention relates to dynamoelectric machines.

More particularly the present invention relates to that class of dynamo electric machines for use with internal combustion engines and storage batteries in which systems the dynamo electric machine supplies the motive power for starting the internal combustion engine and, when driven by said engine, sets up the electro-rnotive force required to charge the storage battery and so ly the lights.

e starting of an internal combustion engine by an electric motor requires for a brief period a dynamo electric machine having the capacity of receiving a considerable amount of electrical energy from the storage battery or other source, while the lighting and recharging apparatus requires, for a much longer period of time, amachine ca able of elivering a very much smal ier amount of electrical energy. a

' An object of the resent invention is to provide a dynamo eectric machine which may be readily converted from a motorto a generator an which is especially adapted to the peculiar conditions of automobile starting and lighting apparatus.

A further object is to provide a dynamo electric machine of the double armature type which is cheap to manufacture and is provided with a minimum of coils.

A further objectis to provide a dynamo electric machine of the engine starting type which is inherently regulated to maintain the generating current within safe limits.

A further object is to provide an automobile starting and lighting system which is simple and reliable 1n operation.

Other objects will appear as the description rooeeds.

Be string to the drawings Fi we Lshows a cross-sectional view of a doub e armature dynamo electric machine.

Specification of Letters Intent.

Patented Oct. 14, 1919.

Benewed February 11, 1919. Serial No. 270,6 1.

. Fig. 2 shows the two armatures with gear- 111 which may be used therebetween;

ig. 3 shows another viewof the geararm'aturesare associated with the pole pieces as indicated in the drawing. Armature 4 is provided with a few turns of relatively heavy wire, while armature 5 is provided with a much greater number of turns of relatively fine wire. Connected to the shaft of armature 4 is a pinion ,6 adapted to mesh with the gear 7 which is associated with the shaft of armature 5 through an overrunning clutch, 8, which may be of any of the well known types. The function of the overrunning clutch is to connect the armatures 4 and 5 together while motoring, whereby they will act 'cumulatively to produce a big torque, but to permit the armature 5 to run free of the armature 4 under generatin conditions, as will beexplained more in etail later. Though the two armatures are shown as cooperatm through an overrunnmg clutch, it is to e understood that the present invention is independent of the overrunning clutch, the latter being disclosed merely for the reason that it is a well known device and is therefore convenient in explainin the invention. Any construction may used which will operate to connect the two armatures together or to a common operating member during the motori period an which will permit the arms re 5 to run free of armature 4 during the generating period.

Referri now to F1 4, which represents one em iment oft e resent invention,

switch casing at 13 Said switch casing is shown as provided with four stationary com tact 18, while 16 and held arts substantiall equally tacts 14, 15, 16 and 17. of which H and 15 are adapted to be bridged by movable con- 17 are adapted tov be bridged by movable contact 19. Contacts 18 and 19 are mounted to move together upon movement of the spring-pressed n1anually operated member 20. The circuit connections established when said manually operated member is moved will be described hereinafter. An automatic switch 21, which may be of any preferred provided in one of [he leads bctweenthe armature 5 and the storage battery 12.

As shown in Fig. 4 the dynamo-electric machine is not operating. lVhen the operator desires to start the engine, (not shown) he will 'move the member 20, thus bridging contacts 14 and 15 b means of the contact 18, and also bridging contacts 16 and 17 by means of contact- 15!. Circuit may now be traced from the left hand side of the stora battery to the point 22, whence branch circuits lead through armature 4 and armature 5. The branch circuit through armature 4 may be traced contacts 15, 18 and 14 through the series winding 9. back to the battery. t this time, it will be noted, the automatic switch 21 is open. The branch circuit through armature 5 ma be traced through contacts 17, 19 and 16 ackto thebatte y. A small amount of current will be diverted around armature 5 through the shunt coil 11. The series coils 9, 9, are wound to direct the flux through armature 4 and through armature 5 and pole piece 3. The coil 11 tends to armature 5, but in practice, due to the preponderance of the series coils and due to the greater length of flux ath due to the length of pole piece 3, the eliiact of this shunt coil is almost negligible. It will be observed that the top part of the field magnet frame constitutes a consequent pole for the armature 4. The two armatnres will rotate and, being mechanically connected, either together or to a common member, they will act cun'lulatively to produce a high torque for starting purposes.

Armatures 4 and 5 are when motoring the (I. E. in each armature is less than pressed across the brushes. Therefore, there will he no interchange of current between the armaturcs. For this purpose the machine is constructed with the ratio of the number of active conductors in the two armaturcs in ihvcrse proportion to the speed ratio of said armatures. As the magnetic on both arruzzturcs, it ill be obvious that by the above arrangement and construction, the same lichl flux is cut'by the same number of conductors per given pcriod'of time.

so designed that F. generated construction, is

. shunt coil 11-.

stationary contacts, 23, one bridging contact 26,

shunt increase the flux through i be directed around armature the voltage im-- battery, the automatic switch, 21 will close.-

Circult may now be traced from armature 5 through the storage battery, series winding 9, automatic switch 21, series winding 10, back to the armature 5.

Coils 9 and 10 are connected to set up an opposing action Consequently the current delivered by the machine will" be held to a safe value.

Referring now toFig. 5, tric machine therein disclosed is similar in most respects to that disclosed in Fig. 4, but

there are some differences in the connections of the various windings. The le pieces 2, 2, are supplied with series win ings 9, 9, as in Fig. 4. tomatic switch lead between the armature 5 and 12. The shunt coil 11 is connected across the armature 5 through the series coil 10, said coils 10 and 11' being reversely wound.

he switch casing 13 is provided with three 21 are also provided in a held away from said stationary contacts. g

When the o mtor desires to start the engine (not s own) in the arrangement shown in Fig. 5, he will move the member 20, thus bridging contacts 23, 24 and 25. Circuit may now be traced from the left hand side of the battery through the series ooils- 9, 9, to the point 22, whence branch circuits may be traced through armature 4 to' contact 23 and through contact 24. From these contacts, circuit' ma be traced through brid 'n contact26 and stationarycontact 25, ac to the batte At this time the automatic switch 21 will be open. A small amount of current will differentially wound coils 11 and 10. Insismuch as the coil11-will be woundwith a large number of turns, while coil 10 will be wound with comparatively few turns, coil 11 will predominate. It will be clear that flux through pole pieces 2, 2, will divide, part threading through armature 4 and the remainder through armature 5. The redominating influence of coil 11 will tend to increase the flux through armature 5, but in practice, due to the preponderance of the series coils and the flux path due to the length of pole pie'tio --l,- the preponderatiug effect of shunt coil 11 is almost negligible, The armatures 4 a ml the dynamo elec- 5 through the due to the greater lcngtlf o1 to the flux developed by the series winding 10 and an authe battery 24 and 25 andwith normally spring '15 will therefore coiiperate as described in 7 and 25,.disconnecting the battery from the dynamo-electric machine. The engine will drive armature 5 but armature i will be disconnected from said engine as explainedewe; When armature 5 develops a sulficient voltage to charge the storage be ttery,

the automatic switch will close and current will bedelivered from armature 5 through the series coils 9, 9, battery 12, automatic switch 21, series coil 10, back to armature 5. Series coils 9, 9, and 10 will set up oping influences to shunt coil 11 and will li riiit the current output of the machine to a safe value.

"Two embodiments of the present invention have been described in detail. Many modifications may be made in the embodiments disclosed. It is intended to include in this case all such modifications that an within the scope of the invention as defined by the appended claims.

Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is:-

1. In. a dynamo electric machine, a pair of rotatable ermatures, a field frame having opposed pole piecesfor supplying flux to said armatures, a third pole piece associated with one of said a-rmnturcs and adapted under certain circumstances to oppose and overcome the flux supplied by said opposed pole ieces.

2. l n a. dyntuno electric npichine, :1 pair of rotatable armaturcs, means synnnctrically arranged with rcspcwt to said nrnmtures for supplying flux thereto, menus responsive to the voltu 'e developed across one of said armatures or supplying flux thereto, said last mentioned means being adapted, under cer tain circumstances to oppose and overcmne the flux from said syl-mnetricnlly arranged means through said one armature.

3. In a dynamo electric n'mchinc, a pair of rotatable arnmturcs, means syn nnct rical ly, arranged with respect to saidnrnnitures for supplying flux thereto in parallel paths. means responsive to the yoltngc developed across 'one of said armaturcs for supplying flux.thereto, said last mentioned means being adapted, under certain circumstances, to oppose and overcome the flux from said symmetrically arranged means through said one armature.

4-. In a. dynamo electric machine, a pair of rotatable armatnres, series field coils for supplying flux to said t l-matures in parallel paths, a shunt wound coil for supplymgflux to one of said armatures, a. series coil conj nected with said shunt wound coil, said series coil being wound to oppose the efi'ect of said shunt .011 during oration.

5. In a dynamo electric machine, a pair of rotatable armntures adopted to coiiperute to produce at high torque,.fone of which, when certain stages of driven, is adapted to act in; a generating arr,

mature, a pair of series field coils arranged in a line between said armntures for supplyurallel paths, a shunt wound coil practical y ineffective at certain stages of operation but adapted to supply} I ing flux thereto in useful flux during generating operations,

and a series coil connected to said shunt coil but wound differentially thereto whereby to limit the current output of. said machine.

6., In, a dynamo electric machine, a pair, I

of rotatable armatures arranged on parallel shafts, "a field frame having a pair of pole pieces arranged-in a line between said arnuitures, said pole pieces being provided with series wound ,coils whereby to direct flux through said armatures, said field frame havin I, a third pole piece, said third olc piece i'ng provided with a series win ing and a. shunt winding responsive to the voltage,developed across one of said armatures, the windings on said third pole piece being difi'erentml y wound whereby the current output of the machine is held to a safe yalue.

7. In a dynamic electric machine, .a pair of rotatable armatures, means for'direct ing flux through said armatures in parallel paths whereby said amiatures may be caused to rotate, means for supplying flux to one of said armatures, and means opposmg said flux supplying means, said opposing means having an effect pro rtiona] to the current output of said mac ine when acting as a generator. l 8. In a dynamo electric machine, a piiir of rotatable amiaturesada ted to coiipefate as motor armatures but on y one of whichis adapted, to be rotated as a generator arma ture, series field coils for supplying flux to said armatures for motoring, a shunt coil for supplying flux to said one armature for generating, and a third series field coil adapted. during generating, to oppose the eil'ect of said shunt coil.

9. In a. dynamo electric machine, a pair of rotatable armutures adapted to coiipcrate asJnotor armatures but only one of which 1,3 1s,sss

10. A dynamo electric machine havin two a rn'iafures with their axe; in different planes, a field magnet frame having lield poles in an intermediate plane, series coils for ener {giving said field poles, whereby said armatures will form parts of parallel flux paths, and a third pole piece constituting part of one of said atlas, said third pole piece being provided with difl'erentiallr wound se- 10 ries and shunt coils.

11-. A dynamo electric machine having two armaturesadapted to cooperate to produce a high torque when 11101301111}: but only one of which is adapted to operate as a generating 15 armature, means adjacent both arn'mturea for supplyin flux thereto for motoring, means adjacent to only one of said arma-I tnres to supply-flux thereto for generating, and opposing means fo said last; mentioned means responsive to current output of said machine.

12. In dynamo electric machinery, in

. eombination, a pairof rotatable armatures adapted to cooperate as motor armatures hfit only one of which is adapled lobe rotated as a generator armature. series field coils for 31 supplying flux to sand armatures for mm toring, a shunt coil for supplying flux to said one armature for generating and an-i other series field coil adapted, duriug gn-n- In witness whereof, I have hereunto subscribed my name.

' THOMAS R. DU 1 )IS.

.erating, to oppose the efi'ert of said shunt 4e 

